PRMT5 activates KLF5 by methylation to facilitate lung cancer

Arginine methylation patterns in LUAD: defining prognostic subtypes and relevance to immunotherapy

BACKGROUND

Lung cancer remains the leading cause of cancer-related death worldwide, with lung adenocarcinoma (LUAD) being the most common subtype. Arginine methylation, driven by protein arginine methyltransferases (PRMTs) has been connected to cancer biology, particularly in modulating cancer immunity. Thus, developing a PRMTs-related prognostic model might help create more personalized treatment plans for LUAD patients.

METHODS

We conducted an integrative analysis using multi-omics data from LUAD samples within the TCGA and GEO database, focusing on the expression profiles of nine PRMTs. Employing machine learning, we developed a PRMTs-related prognostic model, to evaluate the clinical and immunological features of LUAD patients.

RESULTS

We stratified 440 LUAD patients into two distinct clusters (PRMTCluster A and B), which exhibited significant differences in prognosis and immune infiltration. The PRMTs-related prognostic model, incorporating genes CLIC6, CLDN2, and BPIFB1, was significantly associated with patient outcomes and immune signature. RT-qPCR showed that the expression level of PRMT1, PRMT3, PRMT4, PRMT5, and PRMT7 was significantly upregulated in H1975 and A549 cells than in BEAS 2B cells.

CONCLUSION

We developed a PRMTs-related prognostic model for assessing prognosis and immunotherapy responses in LUAD. This model was vital for developing more personalized and effective treatment plans for LUAD patients.

Aberrant miRNA expression and protein arginine methyltransferase 5 (PRMT5) in cancer: A review

The search for important factors involved in triggering and promoting cancer cell growth and survival has led to the identification of key players, including transcription factors, chromatin remodelers, epigenetic modifying enzymes, signaling molecules, and miRNAs. However, the interplay and crosstalk between some of these factors and the impact they have on tumorigenesis remains largely unexplored. In this review, we focus on type II protein arginine methyltransferase 5 (PRMT5)-mediated epigenetic silencing and its regulatory tumor suppressor miRNAs, as well as the mechanisms by which circular PRMT5 RNA (circ-PRMT5) promotes cancer cell proliferation and survival.

Aloin blocks the malignant behavior of lung squamous cell carcinoma cells and M2 macrophage polarization by modulating the NR3C2/MT1M axis

OBJECTIVE

Aloin, the main active component in Aloe vera (L.) Burm. f., has shown promising anti-tumor effects. This study investigated the impact of aloin in lung squamous cell carcinoma (LUSC) and explored its functional mechanism.

METHODS

We analyzed the viability, migration, invasion, proliferation, and apoptosis of two LUSC cell lines after treatment with aloin. Target molecules of aloin and downstream target transcripts of nuclear receptor subfamily 3 group C member 2 (NR3C2) were predicted by bioinformatics. The biological functions of NR3C2 and metallothionein 1 M (MT1M) in the malignant properties of LUSC cells were determined. A co-culture system of LUSC cells with monocyte-derived macrophages was constructed. Mouse xenograft tumor models were generated to analyze the functions of aloin and NR3C2 in the tumorigenic activity of LUSC cells and macrophage polarization in vivo.

RESULTS

Aloin suppressed malignant properties of LUSC cells in vitro. However, these effects were negated by the silencing of NR3C2. NR3C2 was found to activate MT1M transcription by binding to its promoter. Additional upregulation of MT1M suppressed the malignant behavior of LUSC cells augmented by NR3C2 silencing. Analysis of the M1 and M2 markers/cytokines in the macrophages or the culture supernatant revealed that aloin treatment or MT1M overexpression in LUSC cells enhanced M1 polarization while suppressing M2 polarization of macrophages, whereas NR3C2 silencing led to reverse trends. Consistent findings were reproduced in vivo.

CONCLUSION

This study demonstrated that aloin activates the NR3C2/MT1M axis to suppress the malignant behavior of LUSC cells and M2 macrophage polarization. Please cite this article as: Chen YN, Lu JY, Gao CF, Fang ZR, Zhou Y. Aloin blocks the malignant behavior of lung squamous cell carcinoma cells and M2 macrophage polarization by modulating the NR3C2/MT1M axis. J Integr Med. 2025; 23(2): 195-208.

Arginine methylation and respiratory disease

Arginine methylation, a vital post-translational modification, plays a pivotal role in numerous cellular functions such as signal transduction, DNA damage response and repair, regulation of gene transcription, mRNA splicing, and protein interactions. Central to this modification is the role of protein arginine methyltransferases (PRMTs), which have been increasingly recognized for their involvement in the pathogenesis of various respiratory diseases. This review begins with an exploration of the biochemical underpinnings of arginine methylation, shedding light on the intricate molecular regulatory mechanisms governed by PRMTs. It then delves into the impact of arginine methylation and the dysregulation of arginine methyltransferases in diverse pulmonary disorders. Concluding with a focus on the therapeutic potential and recent advancements in PRMT inhibitors, this article aims to offer novel perspectives and therapeutic avenues for the management and treatment of respiratory diseases.

Role and potential therapeutic value of histone methyltransferases in drug resistance mechanisms in lung cancer

Lung cancer, ranking second globally in both incidence and high mortality among common malignant tumors, presents a significant challenge with frequent occurrences of drug resistance despite the continuous emergence of novel therapeutic agents. This exacerbates disease progression, tumor recurrence, and ultimately leads to poor prognosis. Beyond acquired resistance due to genetic mutations, mounting evidence suggests a critical role of epigenetic mechanisms in this process. Numerous studies have indicated abnormal expression of Histone Methyltransferases (HMTs) in lung cancer, with the abnormal activation of certain HMTs closely linked to drug resistance. HMTs mediate drug tolerance in lung cancer through pathways involving alterations in cellular metabolism, upregulation of cancer stem cell-related genes, promotion of epithelial-mesenchymal transition, and enhanced migratory capabilities. The use of HMT inhibitors also opens new avenues for lung cancer treatment, and targeting HMTs may contribute to reversing drug resistance. This comprehensive review delves into the pivotal roles and molecular mechanisms of HMTs in drug resistance in lung cancer, offering a fresh perspective on therapeutic strategies. By thoroughly examining treatment approaches, it provides new insights into understanding drug resistance in lung cancer, supporting personalized treatment, fostering drug development, and propelling lung cancer therapy into novel territories.

GlPRMT5 inhibits GlPP2C1 via symmetric dimethylation and regulates the biosynthesis of secondary metabolites in Ganoderma lucidum

PRMT5, a type II arginine methyltransferase, is involved in transcriptional regulation, RNA processing and other biological processes and signal transduction. Secondary metabolites are vital pharmacological compounds in Ganoderma lucidum, and their content is an important indicator for evaluating the quality of G. lucidum. Here, we found that GlPRMT5 negatively regulates the biosynthesis of secondary metabolites. In further in-depth research, GlPP2C1 (a type 2C protein phosphatase) was identified out as an interacting protein of GlPRMT5 by immunoprecipitation-mass spectrometry (IP-MS). Further mass spectrometry detection revealed that GlPRMT5 symmetrically dimethylates the arginine 99 (R99) and arginine 493 (R493) residues of GlPP2C1 to weaken its activity. The symmetrical dimethylation modification of the R99 residue is the key to affecting GlPP2C1 activity. Symmetrical demethylation-modified GlPP2C1 does not affect the interaction with GlPRMT5. In addition, silencing GlPP2C1 clearly reduced GA content, indicating that GlPP2C1 positively regulates the biosynthesis of secondary metabolites in G. lucidum. In summary, this study reveals the molecular mechanism by which GlPRMT5 regulates secondary metabolites, and these studies provide further insights into the target proteins of GlPRMT5 and symmetric dimethylation sites. Furthermore, these studies provide a basis for the mutual regulation between different epigenetic modifications.

A comprehensive integrated gene network construction to explore the essential role of Notch 1 in lung adenocarcinoma (LUAD)

The heterogeneous biological landscape of non-small cell lung cancer (NSCLC) is largely attributed to the activation of Notch signalling pathway. Among the Notch family transmembrane proteins, neurogenic locus notch homolog protein1 (NOTCH1) is a putative oncogene in NSCLC which activates the pathway as negative prognostic factor. This study aims to explore integrated network approach in lung adenocarcinoma (LUAD) especially linked to the notch pathway and its receptors. Our gene set enrichment analysis reveals the key Notch pathway genes are predominantly down regulated in LUAD. There were 675 genes with a total of 6517 functional interactions and 6 densely connected clusters of 38 miRNAs, 84 transcription factors with 156 edges identified through network construction. Here we report five key genes namely NOTCH1, CDH1, ERBB2, GAPDH and COL1A1 significantly enriched in Notch pathway which are further validated through the KM plot, box plots, stage plots and TIMER analysis. In addition, the NOTCH1 receptor is strongly linked to the immune checkpoint inhibitor CD274 (PD-L1) and can be considered as prognostic marker and tumour suppressor gene in LUAD which surely provide the basis for early diagnosis and futuristic immunotherapeutic targets for LUAD.

PRMT5 as a Potential Therapeutic Target in MYC-Amplified Medulloblastoma

MYC amplification or overexpression is most common in Group 3 medulloblastomas and is positively associated with poor clinical outcomes. Recently, protein arginine methyltransferase 5 (PRMT5) overexpression has been shown to be associated with tumorigenic MYC functions in cancers, particularly in brain cancers such as glioblastoma and medulloblastoma. PRMT5 regulates oncogenes, including MYC, that are often deregulated in medulloblastomas. However, the role of PRMT5-mediated post-translational modification in the stabilization of these oncoproteins remains poorly understood. The potential impact of PRMT5 inhibition on MYC makes it an attractive target in various cancers. PRMT5 inhibitors are a promising class of anti-cancer drugs demonstrating preclinical and preliminary clinical efficacies. Here, we review the publicly available preclinical and clinical studies on PRMT5 targeting using small molecule inhibitors and discuss the prospects of using them in medulloblastoma therapy.